With the rapid development of Internet technologies and applications and the rapid growth of Internet users, a communications system has an increasingly high requirement on data transmission performance. A multiple-antenna transmission policy is mostly used at present to obtain better bit error rate performance and a higher data transmission rate. During multiple-antenna transmission, a spatial modulation (SM) technology is most widely applied.
The spatial modulation technology uses a multiple-antenna structure in a manner of mapping some data bits to quadrature amplitude modulation (QAM) symbols and mapping the other data bits to transmit antenna serial numbers. For example, when to-be-transmitted data bits are 010, 0 corresponds to a first transmit antenna, and 10 corresponds to a modulation symbol 1−i; and when to-be-transmitted bits are 111, 1 corresponds to a second transmit antenna, and 11 corresponds to a modulation symbol −1−i. In this way, the modulation symbol 1−i is transmitted by using the first transmit antenna, and the modulation symbol −1−i is transmitted by using the second transmit antenna. In comparison with other multiple-antenna transmission schemes, the spatial modulation technology features simpler transmitter processing and low decoding complexity of a receiver, and does not require antennas to strictly synchronize with each other, and therefore has better performance in a particular channel condition.
However, in an existing spatial modulation technology, a group of data bits are transmitted by using one antenna after being mapped to modulation symbols, and when a transmit antenna selected according to an antenna serial number is right in deep fading, transmission interruption is caused. Therefore, transmission reliability of the existing spatial modulation technology is low.